Broach



Oct. 15, 1940. J. DRABIK 2,217,659 I BROACH Filed Aug. 1, 1938 3 Sheets-Sheet 1 IlIl I I INYENTOR.

ATTORNEY.

OCt. 15, 1940. V J. DRAB|K 2,217,659

BROACH Filed Aug. 1, 1938 3 Sheets-Sheet 2 IN VENTOR.

J se fa firm A TTORNEY.

BROACH Filed Aug. 1, 1938 5 Shets-Sheet s "mum! INVENTOR.

ATTORNEY.

Patented Oct. 15, 1940 UNITED STATES PATENT OFFICE 12 Claims.

The present invention relates to a die or a broach for cutting and finishing lateral edges in radial or arcuate portions of grooves and correspondingly shaped complementary collars for interfitting the same and for providing a hermetical seal therebetween in casings intended to be air-tight and hermetically sealed, The casings used for electrical motors or generators which in turn are intended to be used in mines, the interlocking fitting between two or more parts of a casing must be air-tight to prevent penetration of gas and consequent explosion.

Gas and air-tight casings of the character indicated are usually made in two parts, one of them being provided with a rectangular or square groove, usually having arcuate portions connecting lateral straight portions thereof, and the other with a correspondingly shaped complementary collar adapted to fit within the groove of the first part. Said groove and collar provide an air-tight fit so that no air or gas may pass therebetween into the casing or its inner cavity which provides a housing for a motor or generator. These arcuate or radial portions of the groove and the collar present a difficult problem in making the same, because even a small deviation from the proper arcuate or radial line during the process of forming the radial or arcuate portion of the groove or of the collar, will render the groove I or the collar, or both, not air-proof and hence the entire casing under those circumstances would have to be discarded with the resultant waste in material and labor.

Hence the primary object of the present invention is the provision of a suitable die or broach for cutting the lateral edges of the radial portions of the groove and a correspondingly shaped collar so that the two may interfit in order that the same may provide a proper seal so as to render the casing air-tight.

Another object of the present invention is the provision of a method of cutting the lateral edges of radial portions of the groove and a correspondingly shaped collar so as to make the two form a proper seal and become air-tight.

With the above general objects in View and others that will appear as the invention is better understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

In the drawings forming a part of this application, and in which like designating characters refer to corresponding parts throughout the several views; v

Fig. 1 is a perspective View, on a reduced scale, of a metallic block out of which one part of the casing is made;

Fig. 2 is a top-plan view on an enlarged scaleof one part of the casing partially completed. The view illustrates one step in the method of making a groove in the metallic block;

Fig. 3 is a cross-sectional View on line 33 of .10 Fig. 2, with broach in position preparatory to cutting a radial portion of the groove;

Fig. 4 is a cross-sectional View on line 4-4 of Fig. 2, showing the breach in elevation in proper position preparatory to cutting a, radial portion of the groove;

Fig. 5 is a top-plan elevational view of the casing with the groove completed;

Fig. 6 is a cross-sectional View. on line 66' 0f Fig. 5; V 20 Fig. '7 is a perspective view of the broach for finishing the radial portion of the groove;

Fig. 8 is a top-plan view of the other part of the casing, partially completed, illustrating one step in the method of making a collar and finishing radial portions thereof to fit into a corre sponding portion of the groove shown in Figs. 2 and 5;

Fig. 91s a cross-sectional view on line 9-9 or" Fig. 8 with a cross-section of a broach in position preparatory to finishing the sides of the collar;

Fig. 10 is an enlarged cross-sectional viewon line |0lil of Fig. 8 showing the breach in ele-. vation, in position preparatory to its employment for cutting or striking out the sides in the radial portion of the collar;

Fig, 11 is a top-plan view of the completed collar portion of the casing;

Fig. 12 is a cross-sectional View on line l2l2 of Fig. 11;

Fig. 13 is a perspective view of a broach employed for finishing radial portions of the 001- lar;

Fig. 14 is a fragmentary top-plan view of a partially completed metallic block forming a groove part of the casing wherein two adjacent cavities are made, illustrating one step in the method of finishing the radial sides of a groove;

Fig. 15 is a similar view illustratingone step in 5 the method of finishing the radial sides of'a collar intended to fit into the groove of the type shown in Fig. 14;

Fig. 16 is across-sectional view on line l6-I6 of Fig; 15, showing a breach of a modified form, 55

in position preparatory to finishing or striking the radial sides of the collar illustrated in Fig. 15;

Fig. 1'7 is a cross-sectional View on line I'l-l'i of Fig. 14 with a die of a modified form in position preparatory to striking out or finishing the sides of the groove shown in Fig. 14;

Fig. 18 is a cross-sectional view on line i8-l8 of Fig. 15 showing the broach in elevation and in position preparatory to striking the radial sides of the collar shown in Fig. 15;

Fig. 19 is a cross-sectional view on line iii-l9 of Fig. 14 with the broach in elevation and in position preparatory to striking out and finishing the sides of the groove illustrated in Fig, 14;

Fig. 20 is a perspective view of a broach employed for cutting radial sides of collar shown in Fig. 15; and

Fig. 21 is a perspective View of a broach for cutting radial sides of a groove illustrated in Fig. 14.

Referring to the broaches for cutting and finishing the edges of radial portions of the interfitting grooves and collars in an air-tight casing of the character above indicated, and to the method of finishing and making said radial portions of grooves and collars, as illustrated in the drawings in Figs. 1 to 13, both inclusive, there is shown in Fig. l a metallic block 22 which may be square on horizontal plane. To provide an airtight casing for the purpose of housing therein an electric generator or an electric motor, two such blocks 22 and 22 are employed, and in each a cavity 23 and 2 3, respectively, is made, so that the two cavities would form a housing when the two blocks are placed face to face. Thereupon in one of said blocks, having a central cavity 23, a groove, generally indicated by 25 in the finished block 22, as illustrated in Fig. 5, is made. Said groove 25 is of a substantially square formation with its corner portions rounded as at 26, to receive a correspondingly shaped collar 2'! with rounded cor-' ner 28 made in a similar block 22, so that when blocks 22 and 22 are laid side by side with their cavities 23 and 2d communicating collar 21 will fit into a correspondingly shaped groove 25 so that the two will form an air-tight seal for the two portions 22 and 22' of the casing.

Referring to the method of making said groove 25, and its radial or rounded corner portions 25, the first step of making said groove and said rounded corner portions 26, is illustrated in Fig. 2. This first step in the method contemplates completely finishing by usual methods the four straight lateral portions 29 of the groove. Thereupon arcuate channel portions 353 are made to connect with the ends of adjacent pairs of said straight lateral portions 29 of the groove. These channel portions 30 at the corners of the ultimate groove 25 are likewisemade by the usual methods. These channel portions 35 are narrower on transverse cross-section than the width on transverse cross-section of the straight lateral completed portions 29 of the groove with the resultant side shoulders 3! at each side of the channel portions 30. When these side shoulders 31 are cut out along lines 32 indicated by dotted lines, the entire groove will have been completed corresponding to the outline of the groove illustrated on Fig. 5.

To cut out said side shoulders ill of the partially completed groove, or more specifically of the channel portions 39 thereof, a suitable broach, best shown in Fig. '7 and generally indicated by 33 is provided. Said broach 33 includes an enlarged head 34 having substantially a triangular formation on horizontal cross-section, from one end of which a substantially arcuate and a reduced base 35 projects. The lateral walls of said base 35 are outwardly tapered as at 36. Said base 35 at its outer termination is provided with an angular groove 37, the tapering walls of which in con junction with the meeting outer tapered walls of said base 35 define apair of spaced, parallel and arcuate cutting edges 38.

Said broach 33 is further provided with integrally formed and downwardly projecting pair of lugs 39, the bottom faces of which may extend slightly below the cutting edges 38 of said broach 33. Said lugs 39 integrally connect with the ends of said base 35 and with said cutting edges 38, as is v clearly shown in Fig. 7. Said lugs 39 are at a right angle relative position and in Width substantially equal the width of the finished straight portions 29 of the partially completed groove 25.

When block 22 has been completed to the extent illustrated in Fig. 2, including portions 29 of the groove, and channel portions 3!], thereupon broach 33 is placed over each of said channel portions 30 in succession, with blocks 39 entering the respective ends of the two adjacent straight groove portions 29, the inner faces of each of said blocks 39 contacting with the outer ends of a pair of side shoulders 3 cutting edges 38 resting upon side shoulders 3i and contacting therewith along lines 32, as is clearly seen in Figs. 3 and 4.

Said broach 33 at its upper end is adapted to receive stock 60 which is attached to head 3 of the broach by means of screw bolt 4i integrally formed with said stock 49 and in threaded engagement with said head 32 through threaded bore 32 made in said head 34. Said stock All may connect with a suitable press machine to exert upon the broach a pressure for forcing the cutting edges 38 of the broach against the side shoulders 3| and for biting into them along lines 32, which are the continuation lines of the side edges of the completed lateral groove portions 29.

This operation will cause said cutting edges 38 to cleanly cut out said shoulders 35 from the metal of block 22 and along said continuation lines 32. The cut out shoulders 32, in form of metal chips will be deflected from the lateral sides of the groove as the operation of the broach progresses, by virtue of tapering walls of angular groove 31, as is obvious, the resulting chips, finding themselves below the broach and Within said angular groove 31. Upon withdrawing of the broach from block 22 the chips which may adhere to the bottom of the finished angular portion 26 of groove 25 may be scraped off by any suitable tool. During the cutting operation of shoulders 3| by broach 33, as hereinabove described, blocks 39 constitute means for limiting a further downward movement of the broach when the same is pressed by a pressing machine against block 22, namely when the bottom faces of said blocks 39 hit the bottoms of the corresponding ends of straight lateral completed portions 29 of the groove, no further cutting operation by cutting edges 38 will be possible. The lateral walls of said blocks 39 contacting with the side walls of the straight completed groove portions 29 constitute means for holding broach 33 in position upon block 22 and for preventing the displacement of broach 33 laterally of the completed side groove portions 29. The inner faces of said blocks 39, contacting with the outer end faces of said shoulders S! prevent the broach from making any movement longitudinally of said completed side groove portions 29 or of corner channel portions 3!], as is clearly seen in Fig. 4.

Upon repeating the cutting operation by broach 33 in connection with each of the arcuate channel portions 30 and upon each pair of shoulders 3| thereof, groove 25, including its radial or arcuate corner portions 26, will be fully completed and the female part of the casing will be ready to receive the other or male part of the casing which will be presently described, including the method of making the same.

Referring to said other or male part of the casing made out of similar block 22 with its center cavity 24, the finished form of which is best shown in Fig. 11, the initial step in the method of making collar 21 including its corner radial or arcuate portions 28, is shown in Fig. 8. This initial step in the method of making said collar 27 including its radial or arcuate portions 28, contemplates making an outer recess 43 upon the face of block 22' and an inner recess 44, with the resultant completed lateral straight portions 45 of collar 21, leaving at the corner portions of the incompleted collar illustrated in Fig. 8 laterally projecting shoulders 46, which when struck out by the broach shown in Fig. 13, and along the lines 41, which in effect are the continuation lines of the lateral sides of the completed straight collar portions 45, will elfect radial or arcuate corner portions 28 of the completed collar 21 illustrated in Fig. 11.

The broach to cut out said laterally projecting shoulders 46 in order to complete collar 21 and its corner radial portions 28, as hereinabove described, is best shown in Fig. 13 and generally indicated by 43 and includes a substantially triangular head 49 on horizontal crosssection. Projecting from the bottom end of said head 49 is a pair of base members50 which are in parallel relative relation, defining an arcuate channel 5|. members 55 and adjacent channel 51 are inwardly tapered as at 52, effecting a constricted mouth for said channel 5!, as seen in Fig. 9. The outer and lower faces of said base members 55 are upwardly tapered as at 53, so that said tapered walls 52 and 53 define a pair of cutting edges 54, both of said cutting edges 54 being on the same plane and in a parallel relation, as seen in Fig. 13.

Said broach 48 is further provided at its lower end and adjacent its lateral sides with four lugs 55, a pair of said lugs 55 being disposed adjacent each end of said channel 5|. Two of said lugs 55 being integrally formed with each of base members 50.

All of said lugs 55 may project slightly beyond cutting edges 54 and affect inwardly disposed faces 55, which are adapted to contact with the outer terminations of shoulders 46 when broach 48 is in position upon the work. The inner faces of each end pair of lugs 55, are in parallel planes and the space defined thereby substantially equals to the finished side collar portions 45, so that when said broach 48 remains in position upon the work, each end pair of said lugs 55 abuts the sides of one of the two adjacent finished side collar portions 45. By virtue of the abutment of the inner faces 56 of said lugs 55 at the ends of said shoulders 46, and by virtueof the abutment of inner faces of said lugs 55 at the finished straight side collar portions 45, broach 48 is prevented to make any shifting movement either longitudinally of the ultimately completed collar 2'! including its corner portions 28, or transversely thereof, as is clearly seen in Fig. 10. When said broach 48 is in position upon the partially completed collar.

The side inner walls of said base shown in Fig. 8, as seen in Figs. 9 and 10, the cutting edges 54 of said broach 48 will be superimposed upon base lines 41, which are the continuation lines of the completed collar portions 45.

Said broach 48 has afiixed thereto a stock 51 through the medium of screw 58. When pressure uponstock 57 is exerted and imparted to said-broach 48 cutting edges 54 will be forced into the metal along lines 41, biting thereinto for the purpose of cutting off said shoulders 46 and along lines 47, the resulting metal chips being deflected laterallyby virtue of the tapering faces 53 of said broach 48, as'is obvious. The end faces of said lugs 55 when striking the bottom of recesses 43 and 44' will limit a further downward movement of the broach while under pressure.

When said shoulders 46 have been struck off the body portion of the incompleted corner radial collarwhich ultimately results in the completed corner portion 28 of said collar 21, the resulting chips which still may adhere at the corners defined by recesses 43 and 44 and the sides of the completed corner portions 23, may be removed or scraped off by any suitable tool.

. It is observed that the size, the width and c0nfiguration of groove 25 in all respects correspond to those of collar 21, with the exception, that collar 21 to an infinitesimal degree is perhaps slightly-narrower than the width of groove 25 so that the former may be able to enter into the latter when force is applied to blocks 22 and 22'. From this it follows that cutting edges 38 and 54 of broaches 33 and 48, respectively, are substantially identical as to the degree of curvature. For the reason above indicated the cutting edges 38 of broach 33 are to an imperceptible degree farther spaced away on transversal plane thereof than the cutting edges 54 of broach 48.

It is further noted that the particular configuration of groove 25 and of collar 21 as shown in Figs. 5 and 11 is for illustration merely, as obviously said groove and collar may be of different configuration. But whichever shape is selected for said groove 25 and collar 21, the

method herein described for making them may be followed, and broaches 33 and 48 with suitably shaped cutting edges may be used. It is obvious that the degree of curvature of cutting edges 33 and 54 in the two broaches, as well as the space defined by each pair of said cutting edges in each broach may be varied. Likewise the particular shape of cutting edges 54 in broach 48, the degree of their spacing and the degree of their curvature may be predetermined so that the same may be complementary of cutting edges 38 in broach 33. v

It is also observed when two completed blocks 22 and 22' as shown in Figs. 5 and 11 are joined together and closed through the medium of groove 25 and collar 21, the cavities 23 and 24, respectively, will define a housing for the purposes hereinabove indicated. When the two blocks are in a relative operative'position the open faces of recesses 43 and 44 of block 22 will contact with corresponding face spaces in block 22 as is apparent from Figs. 5 and 11.

Referring to Figs. 14 and 15 the same show the initial step in the method of constructing complementary grooves and collars of a slightly modified piece of work, which is accomplished by broaches of modified construction best shown in Figs. 20 and 21.

Referring to Fig. ii there is shown a metallic block generally indicated by 59 within which a pair of adjacent cavities 60 are made. This block further includes a longitudinal groove or recess 6i which runs longitudinally with respect to a pair of longitudinally disposed sides of cavities 66. This groove 6| on one side thereof defines a shoulder 62 from which two or more hinge members 63 may project. In conjunction with said longitudinally disposed sides of said cavities 66 said groove defines shoulders 64 which are in longitudinal relation in connection with a pair of longitudinally disposed sides of cavities 66. In the portion of the metal block and centrally of two cavities 68 a groove 65 is made which defines on each side thereof shoulders 66, each of which is a continuation of each of shoulders 64. While making said grooves 61 and 65 care is taken to leave a lateral shoulder projection 6? at each radial corner juncture of shoulders 64 and 66, which lateral shoulder projections 6"! are intended to be cut off by a broach and by a method illustrated in Figs. 17, 19 and 21.

Said broach includes a substantially triangular block 68 from one end of which a substantially T-s-haped base 69 projects. Said broach 68 is provided with three blocks, two of said blocks 76 being in alignment, and one of each of them connecting with the outer end of one branch of said base 69 in one lineal direction. The third block ii integrally connects with the third branch of said base 69 which laterally and perpendicularly projects from the two remaining longitudinally arranged branches of said base 69. Thus, said blocks 16' and ii assume a triangular relative position as is clearly seen in Fig. 21. The lateral faces of the offset branch of said base 69 with which block 'H is connected fiare outwardly along a curve and merge with the adjacent faces of the remaining two branches of said base 69 and in conjunction with the bottom face of said base 69 affect a pair of cutting edges ?2. Centrally of said base 69 and along the offset branch thereof the base is provided with inwardly tapering faces 73 which de fine a triangular recess 14.

The curvature of said cutting edges 12 of broach i8 corresponds to the curved line constituting a continuation line of the outer lateral faces of shoulders 64 and 66, which lines are indicated by dotted lines 15 in Figs. 14 and 17.

For cutting away lateral. shoulder projections 63, being the next step of the operation in the method, broach 68 is placed over the work in such a manner that each of lugs 16 fits within recess 65, the inner face of each of said lugs contacting with the adjacent end of each lateral shoulder projection 67, it being observed that the width of each of said lugs 10 corresponds to the width of the finished recess 6| so as to maintain broach 68 in position and to prevent its movement transversely of said recess 6i. Lug 1i will find itself within recess 65, its inner face abutting the adjacent ends of said lateral corner shoulder projections 61, as is seen in Figs. 17 and 19. When broach 68 is in that position cutting edges 12 thereof will be disposed above said lateral corner shoulder projections 61 and will be superimposed thereon along lines 15. Upon imparting a pressure upon said broach 68 by any suitable machine through the mediumof stock 16 connecting by screw H with said broach 68, cutting edges 12 will be caused to bite into said lateral corner shoulder projections 67 and to cut off the same from the body of the metal along lines 15. The metal chips will be deflected by tapered walls 13' into groove 1'4 along the offset portion of base 69 as well as laterally of the remaining portions of said cutting edges '12, the other branches of said base 69 being likewise suitably tapered so as to deflect said lateral corner shoulder projections 6'! during the process of cutting the same.

When lugs '16 and II will come in contact with the bottoms of recesses 6| and 65, respectively, at the exertion of the pressure at broach 68, further cutting by cutting edges 62 into the metal will be prevented, said lugs) '10 and H thus act as means to limit further operating movement of said broach 68. Upon removal of broach 68 from the work the chips resulting from the lateral corner shoulder projections 61 and adhering to the bottom of recesses 6| and 65 and in the space at the juncture therebetween, may be removed by any suitable tool.

Thus, from the hereinabove description it will be seen that on cutting off the lateral corner shoulder projections 61 from the radial lateral surfaces of shoulders 64 and 66 along lines I5, said surfaces will present uniform faces and will be upon continuation plane of the lateral faces of ridges 64 and 66.

The ridge which will be complementary of recesses 6i and 65 and defined by shoulders 62, 6d and 66, upon cutting off lateral corner shoulder projections 61. and one step of the method of making the same is illustrated in Fig. 15, showing block '18 with twospaced cavities 19 made therein, which cavities will be complementary of cavities 66 for making a pair of adjacent housings for the purpose hereinabove described. As a preliminary step in the method one recess 88 along the edge of each cavity 19 is made and said edge of said recesses 80 includes curving portion 81. Along the outer edge of block 78, a recess 82 is made, by virtue of which arrangement a T-shaped ridge 83 results, having curving sides along the curving portion 8! of recess 86, leaving, however, on each side of said recess 83 and along its curved portion, laterally projecting radial shoulders 84 which will be subject for cutting by a broach illustrated in Figs. 16, 18 and 20 along the dotted lines indicated by 85.

Referring to the broach for cutting laterally projecting radial shoulders 84, the same includes a substantially triangular block 86 having a T- shaped recess 81 at one of the ends of block 86. The tapering sides 88 made in said block 66 in conjunction with the inwardly tapering sides 89 of said recess 8?, a pair of cutting edges 90 result. These cutting edges include curving portions correspondingto the curvature of lines 85 which are the bases of laterally projecting radial shoulders 84. Adjacent each lateral opening of said recess 8'! a pair of spaced lugs 9! is provided, said lugs may be slightly raised above the horizontal plane along said cutting edges 96. The spaces defined by each pair of said lugs 9| substantially equals the width of straight portions of ridge 83. On placing said broach 86 upon block 18 completed to the extent illustrated in Fig. 17, each outer pair of said lugs 9| will laterally embrace the faces of the straight portions of said ridge 83, and the inner faces of the adjacent lugs 91 will contact with the ends of laterally projecting radial shoulders 8 By this means no lateral displacement. of broach 86 with relation to ridge 83 will be possible, and when in that operative position cutting edges 99 will be superimposed on said laterally projecting radial shoulders. 8d and along their lateral bases defined by lines 85. Said broach 86 is provided with a disengageable stock QZthrough the medium of which any pressure exerted thereon by any suitable machine will impart the pressure to broach 86 which in turn will cause cutting edges Ell to pierce the metal along lines 35 for cutting off said laterally projecting radial shoulders 8 The cutting operation of said cutting edges 99 will be continued until the bottom faces of lugs 91 will come in contact with recesses 89 and 82, said lugs constituting means for limiting further downward movement of said cutting edges 9!! When the pressure at the broach through stock 82 is continued.

Due to the outer tapering faces 88 during the cutting operation of said laterally projecting radial shoulders 86, the same will be deflected away from their base lines 85, and when the cutting operation has been completed, the resulting metal chips still adhering to the bottom of recesses I may be removed by any suitable tool.

When the operation for cutting lateral shoulder projections 6? and laterally projecting radial shoulders 86 by. action of broaches 68 and 86, respectively, has been completed, T-shaped ridge 83 will be receivable within recesses 6i and 65, recesses 80 receiving therewithin ridges 6d and 66 and recess 82 receiving ridge 62. These parts will be closely interfitting and complementary of each other so as to prevent entrance of air or gas into jackets defined by cavities 60 and 19.

Of course, the degree of curvature of cutting edges 12 and' Si! in broaches 63 and 86, respectively, is predetermined so that upon cutting off lateral shoulder projections 6'1 and laterally projecting radial shoulders 84, respectively, the bases from which the two were out along lines 15 and 85, respectively, Will form closely interfitting and intercontacting surfaces.

As already indicated lugs 39, 55, 10 and 9| in the respective broaches 34, G9, 68 and 86 may be elevated or slightly removed from the plane of the respective cutting edges 38, 54, i2 and 99. By virtue of this arrangement said cutting edges upon completion of the cutting operation will not reach the plane co-extensive with the plane of the respective completed groove portions 29, recesses 43 and M, recesses 61 and 65, and recesses 8i.

To complete the cutting operation of. said lateral shoulder projections 67 along and upon their Vertical base lines, instead of using any particular or suitable tool, broaches such as herein described may be used of a modified construction. The modified construction would merely consist, in having the outer faces of lugs 39, 55, i0 and 9! in the respective broaches remain by their outer end faces on a plane co-extensive with the plane of the respective cutting edges.

From the hereinabove description it will be seen that broaches 68 and constitute a modification of broaches 33 and 58, the underlying principle of use and operation of all of the broaches shown and herein described is the same. Obviously further structural modifications of broaches and of their cutting edges is possible, all depending upon the particular work intended to be performed by the particular broach, and the show-, ng and describing herein of some types of broaches for performing a particular work, is not to be to perform a modified type of work.

While there is described herein a preferredem bodiment of the present invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

What I claimas new is:

l. A broach for making grooves in a body hav ing a completed portion of the groove and a lateral shoulder projection in a partially completed portion of the groove and which said lateral iiishoulder projection extending from a base line correspondingto the continuation line of the lateral side of the completed portion of the groove, comprising a cutting element for cutting out said lateral shoulder projection along said base line, said cutting element having a contour corresponding to the contour of said base line, and means for engaging said broach with said body at the completed groove portion thereof for maintaining said cutting element in alignment with said base line during cutting operation.

2. A broach comprisingv a head, a pair of spaced cutting elements upon said head, said elements being adapted to cut into a body upon application of pressure to said head, and a plurality of projections extending from said headand con necting with said cutting elements, said projections being adapted to engage said body for preventing lateral movement of the broach during cutting operation.

3. A broach comprising a head, a cutting element upon said head, said element being adapted to cut into a body upon application of pressure to said head, and a projection extending from application of pressure to said head, and a projection extending from said head adjacent each end of a pair of said cutting elements, said projections being adapted to engage said body for preventing lateral movement of the broach during cutting operation. v

5. A broach comprising a head, a pair of spaced, parallel cutting elements upon said head, said elements being adapted to cut into a body upon application of pressure to said head, and a projection extending from said head adjacent each end of a pair of, said cutting .elements, said projections being adapted to engage said body for preventing lateral movement of the broach during cutting operation, said cutting elements and said projections being substantially on the same plane perpendicular to the axis of said head.

6. A broach comprising a head, a cutting ele-' ment upon said head, said cutting element having a face substantially coextensive with the plane parallel to the axis of said head, said element being adapted to cut into a body on application of pressure to said head, and a projection extending from said head for engaging said body for preventing lateral movement of the broach during cutting operation, one wall of said projectiton being in a coplanar relation with said face.

'7. A broach comprising a head, a pair of cutting elements upon said head, each of said cutting elements having a face substantially coextensive with the plane parallel to the axis of said head, said elements being adapted to cut into a body on application of pressure to said head, and a projection extending from said head for engaging said body for preventing lateral movement of the broach during cutting operation, said projection having a pair of opposed walls each of which being in a coplanar relation with one of said faces.

8. A broach comprising a head, and a pair of spaced, parallel cutting elements, each of said cutting elements having a face substantially coextensive with the plane parallel to the axis of said head and a face in an oblique relation therewith for defining a pair of spaced, parallel cutting edges, said cutting edges being on the plane perpendicular to the axis of said head I 9. A broach comprising a head, and a pair of spaced, parallel cutting elements, each of said cutting elements having a face substantially coextensive with the plane parallel to the axis of said head and a face in an oblique relation therewith for defining a pair of spaced, parallel cutting edges, said cutting edges being on the plane perpedicular to the axis of said head, said cutting edges being adapted to out into a body on application of pressure to said head, said oblique faces facilitating the material cut from said body to be deflected away from the plane of movement of said cuttingedges during cutting operation.

10. A broach comprising a head, a cutting element on said head, said cutting element having a face substantially coextensive with the plane parallel to the axis of said head, and a face in an oblique relation therewith for defining a cutting edge, said cutting edge being adapted to cut into a body on application of pressure to said engaging said body for guiding said cutting edge in its movement during cutting operation on a predetermined plane.

11. A broach comprising a head, a pair of spaced cutting elements, each of said cutting elements having a face substantially coextensive with the plane parallel to the axis of said head, and a face in an oblique relation therewith for defining a pair of spaced cutting edges, said cutting edges being adapted to cut into a body on application of pressure to said head, said oblique faces facilitating the material cut from said body to be deflected away from the plane of movement of said cutting edges during cutting operation, and means upon said head for engaging said body for guiding the movement of said cutting edges during cutting operation on a predetermined plane.

12. A broach comprising a head and a cutting element on said head, said cutting element having a face substantially co-axial with said head, and a face in an oblique relation therewith for defining a cutting edge, said cutting edge being adapted to cut into a body on application of pressure to said head, said oblique face facilitating the material cut from said body to be deflected away from the plane of movement of said cutting edge during cutting operation.

JOSEPH DRABIK. 

